การฟัง TOEFL

🎧 บทถอดเสียง

Narrator: Listen to part of a lecture in an environmental science class. Professor: Today we’re going to talk about urban heat islands. As you know, cities tend to be warmer than surrounding rural areas. This is because concrete and asphalt absorb and re-radiate heat, while vegetation and soil in rural areas cool the air through evaporation and shading. But there are ways to mitigate this effect. One common strategy is increasing tree cover. Trees provide shade and release moisture, which can lower surface temperatures significantly. Another approach is using reflective materials on rooftops and pavements. These materials, often called cool roofs or cool pavements, reflect more sunlight and absorb less heat. However, there’s a trade-off: cool pavements can be slippery when wet, and they may not be as durable as traditional materials. So, cities need to weigh the benefits against potential drawbacks. Interestingly, a combination of strategies—more trees, green roofs, and cool materials—often yields the best results, but implementation requires careful planning and community support. Now, let’s consider a specific case study from a city that recently adopted a comprehensive plan...